Grinding of toothed wheels, milling-cutters, and the like.



A. AIGHELE.

GRINDING 0P TOOTHED WHEELS, MILLING CUTTERS, AND THE LIKE.

APPLICATION rum) AUG.8, 1913 1,080,505, Patentd Dec.2,1913.

2 SHEETS-SHEET 1.

AND THE LIKE.

GRINDING 0F TOOTHED APPL 1 ,080 ,505

AICHELE.

BLS, MILLING CUTTERS, TION FILED AUG.8, 1913.

- Patented Dec. 2, 1913.

2 8HBETS-SHEET 2.

UNITED STATES PATENT ornronf.

ALBERT AICHELE, 0F BADEN, SWITZERLAND.

GRINDING OF TOOTHED WHEELS, MILLING-CUTTERS, AND THE LIKE.

Specification of Letters Patent.

Patented Dec. 2, 1913.

Original application filed December 15, 1911, Serial No. 665,895.Divided and this application filed August 8, 1913. Serial No. 783,745.

To all whom it may concern Be it known that I, A BERT Aionnnn, a citizenofthe Swiss Republic, and residing at Baden, Switzerland, have inventedcertain new and useful Improvements in and Relating to the Grinding ofToothcd lVheels, Milling-Cutters, and the like, of which the followingis a specification.

This invention relates to the mutual grinding of toothed wheels, millingcutters and the like bodies. I

It is an essential condition for the smooth 'working of toothed wheelsthat the transmissio-nof power shall be perfectly free fromjolts, thatis to say, in the case of uniform motion of the driving wheel, thedriven wheel or wheels must also have perfectly uniform motion. Tosatisfy this condition, it is necessary that the teeth shall have amathematically accurate profile. In practice, however, such constructionis almost impossible especially in the case of wheels which are hardenedafter manufacture.

This application is a division of applicants application No. 665,895,filed December 15, 1911. x

It has heretofore been attempted to grind the wheels mutually ortogether after manufacture. A satisfactory result has however not beenachieved with the processes known hitherto.

The object of the present invention is to provide a process andapparatus for producing the required shape d uring mutual 1 is a sideelevation; Fig. 2 is a section of the apparatus; Fig. 3 shows means forangularlydisplacing one -of the wheels undergoing grinding with relationto the other, and Figs. 4 to 7 are progressive views showing part of apair of wheels undergoing tion.

grinding, the unground tooth surfaces being serrated merely to indicateroughness.

In the form illustrated the two toothed wheels at and b to be groundtogether, are mounted respectively on the shafts c and d. These twoshafts are driven by friction disks 6 and f which are driven in theirturn by a common friction disk 9, the driving of the disk f beingeffected by the interposition of an idle wheel 72. for reversing thedirection of rotation of the disk f with respect to the disk 6. Thisidle wheel h is pressed by the spring 2' against the disks f and g. Acrank mechanism 70 is provided by means of which the shaft 0 and throughit the toothed wheel a can be moved to and fro in the axial direc- Thescrew spindle Z serves the pur pose of moving the two axles c and dnearer to each other until the disks (3 and f come in contact andtherefore the toothed wheels roll on the pitch circles. The arm m ismounted on the center 0 for the purpose of insuring the driving of e bythe disk 9 in every position.

In order to allow of shifting the position of the toothed wheelsrelatively to their driving device, the wheel e for instance is fixed tothe shaft cl by means of an interposed worm drive p in such a mannerthat by rotating the worm 7) a shifting of the wheel relative to theaxis can be effected.

According to the above arrangement for the purpose of starting theprocess the axles of the two toothed wheels to be ground in, which areat a variable distance apart, are removed so far apart that at firstthere is no contact between the teeth, as in Fig. 4, and then they'aregradually moved nearer to each other until the teeth are in contact,(Fig. 5) but at first only at the points which constitute the greatestdeviation from the ideal shape of the tooth. At the same time one of thetoothed wheels is moved to and fro inthe axial direction by a separatedriving device. This movement is mainly intended to effect thegrindingwith the use of a' grinding material. This axial movement is notintended to accelerate the grinding in, and it affords importantadvantages inasmuch as the grinding in of the toothed wheels under theinfluence of the rotary motion does not alone effect the object. in viewin a perfect manner because under the influence of rotary motion alonerelative movements of the teeth against one another l thicker than thefinal shape, then after carrying out .the present process the profile ofthe tooth will have been completely ground, so as to produce toothedwheels which will mesh with one another with an ideal shape of tooth. Ifthe teeth at the commencement of the operations were thicker than the.thickness required to enable them to work to- 'gether' without. any playwhen finally shaped then at the termination of the operations teeth ofideal form will berproduced which will mesh without play. If the teethoriginally were thinner than required by the ideal form of tooth withoutplay, and could not therefore be ground down to the said ideal form, aspecial a paratus is provided for the purpose of pro ucing a correctform of tooth with some play between the teeth.

Since in the case of mutually engaging toothed wheels it is usuallyrequired to keep to determined pitch circles, the axles should not bemoved nearer to each. other than. the point at which the pitch circlestouch each other. Now in order, when this position of the axles has beenreached, to

' enable the engaging tooth face of the two wheels to be pressedtogether with the requisite pressure for mutual grinding, one of thetoothed wheels to be ground is shifted through a certain angle in thesense for effecting this intimate contact, conveniently by rotating itsshaft relatively to the driving means therefor. lhus the grindingoperation is continued until all parts of the surfaces of the mutuallycontacting tooth faces have been ground and the ideal tooth form hasbeen produced on one face of the teeth as'shown in Fig. 7. Whereupon byshifting this toothed wheel in the other sense roaches by the amount ofthe play between the tooth faces the other face of the tooth can beground. A one-sided pressure on the teeth acting continuously on oneside or the other may also be produced by making the ratio between theperipheral speeds in the driving 7 device of the two axles of thetoothed wheels greater or smaller than the ratio between the toothedwheels to be ground in, and byv this means'a grinding away of one sideor the other of the tooth profile can be efiected. This alteration ofthe ratio of thepair of driving toothed wheels and the. pair of toothedwheels must naturally be made so small that its effect will be equal tothat of the aforesaid continuous shifting of the wheels to be ground inrelatively to the driving device. Non-positive driving devices, forinstance, friction disks, may be employed for driving the axles of thetoothed wheels.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is 1. A method of mutually grinding toothedwheels or the like which consists in mounting two toothed wheels uponseparate shafts, driving each of said shafts moving the wheelsinto meshand supplying an abrasive to the same, as set forth.

2. A method of mutually grinding toothed wheels or the like whichconsists in mountin two toothed wheels upon separate to the same, andimpartinglateral move ment to at least one of said wheels along the axisthereof, as set forth. I

3. A method of mutually grinding toothed wheels or the like whichconsists in mounting two toothed wheels upon separate shafts, drivingeach of said shafts moving the wheels into mesh, supplying an abrasiveto the same, displacing one of the wheels about its axis relatively toits driving means, as and for the purpose described.

In testimony whereof I ailix my signature in presence of two witnesses.

ALBERT AICHELE;

Witnesses:

CARL GUBLER, Aueusr Runes.

